Method of preparing baseball centers



Nov, 25, 1924.

T. S. SHIBE METHOD OF PREPARING BASEBALL CENTERS Original Filed July 19, 1924 .w .Wm du.. M m h T 45 in carrying Patented Nov. 25. 1.924

""HOLIIAS S. SHIRE, 0F PHILADELYEIA, PENNSYLVANIA METHOD F PBEPRING BASEBALL CENTERS.

Original application filed Juliy 19, 19M, Serial No, 7

27,010. Divided and this application filed September 13, 1924. Serial No. 737,569.

1 u (ILL whom t Amay Concern:

15e it known that l, TiioMAs S. Surfin,

a citizen of the United States, and resident of Philadelphia, in the county of Philedeh 5 pliiai and State of Pennsylvania, have invented certain new and useful lmp* ments in Methods of Preparing i311 Centers, ot' which the following is a specification.

My resent invention relates to improvements in base balls of the type having a cork center surrounded by a layer of rubber, such as is shown, for example in Letters Patent of the United States, No. 932,911, dated Aw gust 31, 1909, and in the art of making the same, and is a division of my cri-pending ap lication Serial No. 727,010.

e invention aims to iovide a ball or this character having a cor center provided l with a homogeneous rubber shell in which the center is accurately7 centered or positio'ned.

A Theinvention further aims to provide a ball havi a cork center provided with a rubber enc osing shell of such construction that it can be vulcanized on the center withdestroying the out danger of burning or latter.

' A. further object is to avoid having an air trapped between the sheath and the cor center.

`With these various objects in view, the invention includes the novel method hereinf after described, and particularly defined by 3? yth/e appended claims.

In order thatwthe invention may be better understood, reference is made to the accompanying drawing, in which Figure 1 is a sectional view of a complete 4o ball, and

Fig. 2 is a detail view partly in section and partl in elevation, s owing the cork center an enclosing shell.

Fig. 3 is a sectional view of a mold used out the process. i

Referring by reference characters to this drawing, the numeral l designates a cork sphere designed to form the inner core or center of the ball, and 2 an enclosing sheath or shell of relatively firm and highly resilient rubber which is of homogeneous formation, being vulcanized around and completely enveloping the cork center.

In providing the @Ork Center with as' ho mogeneous vulcanized enclos'ng shell, l have found that unless venting means are provided, there is liability of air being trapped between the cork center and shell which makes the ball erratic in bounding, this tiapp'ng of air being rendered more likely by reason of the cellular structure of thc cork. Furthermore, the entrapped air is expanded during the vulcanizing action and tends to produce distortion, and it has furthermore been found difficult to provide a center with a homogeneous shell in which the cork is accurately centered,` or in other words, is surrounded by a layer or shell of rubber ot uniform thickness. To avoid these various objections, I provide the shell with a plurality of vent passages. These ari referably in the form of cylindrical openings or passages 3, through the wall of the shell from the inner surface to the outer periphery. They are preferably distributed evenlyl throughout the entire circumference of the shell, as shown, and may be left open as hown, in which case they constitute enclosed chambers or cells in the nished ball, as shown in Fig. 1, or they may be filled with a fibrous material which will permit the passage of air. In the formation of my imlproved center, the rubber shell is preferab y formed in two hemispherical sections by the use of molds such as shown for example, in Fig. 3, comprising male and female menibeis 4 and 5, which when fitted t0- gether, provide an enclosed cavity 2 of hemisphercal shape. The rubber compound is placed in this cavity and'subjected to artial vulcanization, the cure being carrie only to such a point as to enable the rubber com ound to maintain its proper shape while eing subsequently manipulated and treated. After two such shells are made they are placed together to form the complete sphere shown in Fig. 2, with the cork center enclosed there-between, the whole then being placed in a ball vulcanizing mold of the customary form and subjected to heat to complete the cure, Wheieu on the edges of the two hemispherioal Shel s are vulcanized together to form a homogeneous shell. The 'rents in the wall of the shell may be formed by roviding any suitable cores or filling mem ers during vulcanization. The forni of mold shown in Fig. 3 affords a very satisfactory means of supplying these vent openings or passa es, though it will be readily understoodgthat many other forms or Ways of accomplishin this are available. In the mold shown in ig. 3, one of the members, as for instance the female meiiiber 5, may be provided with a polar projection 5* which Would form one of the' passages in the shell, and the member 4 could be rovided with a plurality of circumferexr tia y spaced semi-circular projections 4S which would form spaced semicireular recesses in the edge of the shell, and when two half shells were brought together with these reesses in alignment, cylindrical openings or passages would be the result. `Other and in termediate passages would be provided by the use of removable core pins 5*.

If desired, during final vulcanization in the ball mold, the openings in the shell could be filled with core pins. This would not interfere with the venting of the air, as it could pass out around the pins` or they could be made tubular so that air would pass through them, or could be of a porous nature. The air which had passed out throu h the vents would, of course, escape from t e mold by the usual parting' line of the mold.

Having thus described my invention, what I claim is:

L The hereindescrioed method of making a core or center for base balls which consists in forming a pair of partially cured hemispherical sections of rubber compound, assembling said sections in the form y of a sphere with a spherical cork center of fill ing material therein, and subsequentiy eo1upleting the core and vuloanizing the edges of said shell sections together ehile venting the space within the shell.

2. The herendeseribed method of making a core or center for base balls, which oon- Sists of orm'ng a pair of partially cured heinispherical sections of rubber eompound, provided with a plurality of passages through the walls thereof, assemblin said sections with their edges in contact, an with an enclosed cork center, and subsequently completing the vulcanization to join said edges together and form a homogeneous shell,

In testimony whereof, I alix my signa.- ture.

THOMA S S. SHIBE. 

